EN LA DÉCADA DE 1990 UMBERTO PELIZZARI was a young diver from Busto Arsizio, Italy, who was making headlines by breaking world records in constant weight and variable weight freediving. Needing an edge against his archrival, Francisco “Pipin” Ferreras, he sought advice on fins from a friend who was knowledgeable about innovative freediving equipment: Valerio Grassi, founder of Omersub.
Car-racing technology had started using composites, so the two friends designed some prototype composite fins for future trials. Pelizzari’s goal was to eventually exceed 80 meters on a single breath in a constant weight freedive. Using his composite freediving fins, he went on to set numerous records and reached his goal, establishing a new world record with an 80-meter constant weight freedive in October 1999. Bob Talbot’s 2001 IMAX film Ocean Men: Extreme Dive : Extreme Dive (Hombres del océano: buceo extremo) presenta la histórica rivalidad entre Pelizzari y Ferreras.
With nearly 25 years of experience in the dive equipment industry, I’ve witnessed all the changes and advancements in freediving fins. In the 1990s the major manufacturers produced plastic long-blade fins in similar lengths but with subtle differences in the blade geometrics and terminal shapes. Some more advanced designs integrated a bend in the plant of the fin blades where they attach to the foot pockets. Some fins were modular designs with foot pockets connected via clips and screws to the blade; others were molded one-piece designs.
Todavía estaba por verse qué diseño era finalmente mejor. En ese entonces, la teoría elemental era que las palas más rígidas impulsarían más a un buzo. Los buzos que descendían a grandes profundidades necesitaban un mayor empuje, y la flotabilidad negativa adicional superior a 2 o 3 atmósferas requería un impulso adicional de la pala para que el buzo pudiera regresar a la superficie.
Diverse materials — including the fiberglass, Kevlar, carbon fiber, and even clear optical industry materials — were integrated into fins. Freedivers wanting a performance edge experimented with materials that would provide the most efficient propulsion and energy conservation for oxygen-starved freedivers plummeting to and returning from depth.
By the early 2000s a few manufacturers produced and marketed open-heel long-blade fins, not so much for freedivers but for scuba divers who wore booties and wanted a quick on and off slip-in design with straps. These fins were well suited for divers in heavy current, doing long drift dives, and for chasing down students. New materials later changed the game for freediving long-blade fins. The markets went from 95 percent plastic polymer and thermoplastics — fancy names for polyamide and plastic derivatives used in injection molding — to a wide variety of composite materials.
The functionality of freediving fins accelerated from this point forward. What hadn’t changed since the plastic fins of the 1970s now evolved with the use of composite materials for blades and modular thermoplastic multicompound foot pockets that were joined separately to the fin blades.
El cambio a los nuevos materiales para aletas se basó en un deseo de mayor seguridad debido a un aumento de los accidentes de buceo en apnea. Contrario a la creencia anterior de que las palas más rígidas tenían más eficacia a profundidad, resultó ser una receta mortal para los desvanecimientos en aguas superficiales. Los buzos que se sumergían a profundidad necesitaban una rigidez extra para sobrellevar la flotabilidad negativa adicional, pero la mayor rigidez para un buzo en apnea laborioso que se esforzaba por dirigirse a la superficie tensionaba excesivamente los músculos de sus piernas.
Manufacturers concluded that blade stiffness requirements depended on the diver’s body type and stature, perhaps not interpolating the general freediving population. Design evolved to alternate materials for energy and weight savings.
Carbon fiber is generally regarded as the most efficient material for freediving fins — not only for its excellent stiffness-to-weight relationship but also for its responsiveness and reactivity. Properly molded carbon fiber freediving fins with the right stiffness will efficiently propel the diver to depth by minimizing wasted energy.
Como punto de partida general para determinar la dureza o rigidez de las aletas, un buzo que pesa menos de 68 kilogramos (150 libras) normalmente seleccionaría una pala de aleta de rigidez reducida o 20-25. Un buzo que pesa entre 79 y 91 kilogramos (175 y 200 libras) normalmente utilizaría una rigidez media o 30 y un buzo más pesado debería optar por una pala de aleta de rigidez elevada o 40, pero existen excepciones a estas recomendaciones. Algunos instructores y profesionales, por ejemplo, prefieren las palas de aleta que son más rígidas de lo que su estatura indicaría para tener una respuesta y una propulsión más rápidas.
Carbon fin blades are also available in different shapes and lengths. Long but light fins create less fatigue in a diver’s quadriceps. The extra blade length propels the diver with fewer kicks compared with regular-length fins. By displacing larger volumes of water, long fins allow the cadence to slow to longer, smoother, full rotation kicks with less sculling.
Carbon fiber fins weigh about 1 to 1.5 pounds (453 a 680 grams) each, and the foot pockets generally join with a set screw kit to the blade. With closed-heel pockets, divers typically wear 2 mm to 3 mm socks, which are too thin for coldwater divers, who usually use an open-heel strap fin with neoprene boots to keep their feet warm.
The most important variable when choosing a proper fin is the fit of the foot pocket. Once you achieve a comfortable, snug foot pocket, you can easily narrow down the blades based on a few criteria, such as your stature, the depth you most commonly dive, and the type of freediving or sport diving you do — such as spearfishing, photography, depth attempts, or surface-based swimming.
Muchas aletas son modulares, lo que significa que las palas se separan para poder cambiarlas o para que sea más fácil viajar con ellas. Una bolsa para aletas de buceo en apnea adecuada es una excelente inversión para viajar en avión para que pueda empacar sus objetos personales en ella y guardarla en el compartimiento superior. La fibra de carbono es más fuerte que el plástico, y son bastante duraderas cuando se les da el uso previsto.
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